/Engine/Source/Runtime/CoreUObject/Public/UObject/UObjectGlobals.h
Create optional component or subobject. Optional subobjects may not get created when a derived class specified DoNotCreateDefaultSubobject with the subobject's name.
template<class TReturnType> TReturnType * CreateOptionalDefaultSubobject ( [UObject](API\Runtime\CoreUObject\UObject\UObject) * Outer, [FName](API\Runtime\Core\UObject\FName) SubobjectName, bool bTransient ) const